216533 has 4 divisors (see below), whose sum is σ = 217728. Its totient is φ = 215340.

The previous prime is 216523. The next prime is 216551. The reversal of 216533 is 335612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 216533 - 2¹² = 212437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263 + ... + 708.

It is an arithmetic number, because the mean of its divisors is an integer number (54432).

2²¹⁶⁵³³ is an apocalyptic number.

It is an amenable number.

216533 is a deficient number, since it is larger than the sum of its proper divisors (1195).

216533 is an equidigital number, since it uses as much as digits as its factorization.

216533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194.

The product of its digits is 540, while the sum is 20.

The square root of 216533 is about 465.3310649419. The cubic root of 216533 is about 60.0493113140.

The spelling of 216533 in words is "two hundred sixteen thousand, five hundred thirty-three".